The present invention relates generally to electrically controlled pneumatic train brake and computer controlled train brake systems, and more specifically, to switching between pneumatic and electrical mode in integrated braking systems.
Computer controlled brake systems or EAB brake control systems are well known as exemplified by CCBI and CCBII available from New York Air Brake Corporation. These systems provide computer controls of the pneumatic control unit for the pneumatic pipes running throughout the train. This allows pneumatic control of the locomotive as well as the individual car brakes. More recently, the industry has been striving to provide electrically controlled pneumatic or electropneumatic brakes on each of the cars and locomotives. This has led to the electrically controlled pneumatic ECP system which is independent of the computer control braking system. An overview of such a system is EP-60 available from New York Air Brake Corporation.
As presently implemented, the ECP system in the locomotive runs in parallel to that of the conventional pneumatic locomotive train controls. Two brake valves are provided, one being the brake valve for the pneumatic braking and the other being the ECP brake valve. Similarly, separate displays are provided for each system. The locomotive or the consist of the locomotives do not respond to the brake commands made by the ECP system since the locomotives respond to pneumatic signals on pipes. Also, the ECP system has its own discrete input from the event recorder and from the locomotive controls to determine penalties.
With the implementation of electrically controlled pneumatic (ECP) or electro-pneumatic (EAB) brakes, there has been discussion of the desirability of integrating the computer controlled braking systems with the electrical controlled pneumatic (ECP) brake systems.
Integrating ECP and EAB brake control systems create mode transition requirements, where the control system must transition to and from the following:
Controlling a conventional pneumatic brake system (i.e. DB-60, etc.)
Controlling an electronic trainline brake system (i.e. EP-60, etc.
With non-integrated systems, the interaction is independent of each other for entering and exiting each system mode. The train engineer is provided a separate brake controller for each system, for the independent selection of a desired brake level for each system.
With the integrated system, each system relies on a common brake controller. Therefore during system transition (entering and exiting), where each system warrants opposing brake commands from a common controller, a special control process is required.
The present invention is a method of transitioning between the pneumatic and electric modes of an integrated pneumatic/electro-pneumatic train brake system which includes a brake control having a common operator brake controller. Initially, the control applies the brakes in response to the operator brake controller in the present mode. The control enables the next mode upon a request from an operator and applies the brakes in the next mode to at least the level equal to or greater than applied brakes in the present mode. Once the next mode is verified and the present mode brakes only are released, the control system switch to the next mode.
Wherein the present mode is the pneumatic mode and the next mode is the electric mode, the operator releases the pneumatic brakes by moving the brake controller to release which charges the brake pipe. The brake pipe remains charged in the electric mode. When the brake system is switched to the electric mode, a full service interlock is set. This interlock is released by moving the brake controller to full service position and subsequently back to release position. The electric mode will not be enabled if the speed of the train is more than zero. Similarly, the electric mode will not be enabled if the brake control is not in lead in the pneumatic mode and not in lead in the electric mode.
The brake system includes at least one other brake control in a network with the brake control. When the brake control is switched to the electric mode, the brake control activates the networks and the other brake control monitors the network and switches itself automatically to the electric mode upon detecting that the network is active.
If the other brake control is initially in trail in the pneumatic mode, the other brake control automatically switches to trail in the electric mode. If the other control is in the lead in the pneumatic mode, the other brake control switches to remote in the electric mode. If the other brake controllers change from lead to trail in the pneumatic mode, the other brake control automatically switches into trail in the electric mode. If the other brake control is changed from trail to lead in the pneumatic mode, the other brake control automatically switches into remote in the electric mode.
When the present mode is the electric mode and the next mode is the pneumatic mode, the brake control enables the pneumatic mode in response to a first electric mode cut-out request from the operator. The brake control releases the electro-pneumatic brakes after verification that the pneumatic mode is operational and upon a second cut-out request from the operator. During this transition, both systems are responding to a common brake controller. The brake. control does not release the electro-pneumatic brake if the second cut-out request occurs within a predetermined time period after the first cut-out request. If the train speed is more than zero any time before the second cut-out request, the electro-pneumatic brakes are set to a full service interlock. The pneumatic mode will not be enabled if the brake control is not in lead in the pneumatic mode. The brake control is changed to trail in the electric mode after the brake control has been switched to the pneumatic mode to de-activate the electro-pneumatic brake control and the trainline.
The brake system includes at least one other brake control in a network with the brake control. With a brake control switch to the pneumatic mode, the brake control sends a cut-out status on the network and the other brake control monitors the network and switches to the pneumatic mode upon detecting the cutout status on the network. The brake control is changed to trail in the electric mode after the brake controls has been switched to the pneumatic mode and the network becomes inactive. If the other brake control is in trail in the electric mode, the other brake control switches to the trail in the pneumatic mode. If the other brake control is in remote in the electric mode, the other brake control switches to lead/cut-out in the pneumatic mode.
The method is performed by software stored in the brake system.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.